Schizophrenia is a chronic psychotic illness. Symptoms have their onset in early adult years and last a lifetime, exacting a huge burden of human suffering and posing complex—and still unsolved—treatment questions. Psychotic behavior has been evident from the dawn of human history, but schizophrenia was not conceptualized as an illness until the mid-1800s, and it was not until the 1950s that even palliative treatments were available (Davis 1969). Since the 1950s, when the antipsychotic activity of chlorpromazine was discovered, two generations of antipsychotic drugs have been developed and considerable additional experimentation carried out with complementary treatment approaches (Geyer and Heinssen 2005). The prevailing orientation to pharmacotherapy in schizophrenia, until now, has been to prescribe a single drug directed toward a comprehensive treatment of the illness, like prescribing insulin to treat diabetes. The orientation has not been optimally successful, yet it has driven drug discovery until now.